Lock-up means for overriding drives



Aug. 2, 1960 F. M. LITTELL ETA!- 2,947,537

LOCK-UP MEANS FOR OVERRIDING DRIVES 3 Sheets-Sheet 1 Filed May 2, 1958 UM I a: a n l llllllT g- 1960 F. M. LITTELL ETAL 2,947,537

LOCK-UP MEANS FOR OVERRIDING DRIVES Filed May 2, 195B 3 Sheets-Sheet 2 fiz/era 0215. wa 50% 6,

$5 50 @uafog.

Aug. 2, 1960 F. M. LITTELL ET AL 2,947,537

LOCK-UP MEANS FOR OVERRIDING DRIVES Filed May 2, 1958 3 Sheets- Sheet 3 J75 J70 J74 Unite States Patent LOCK-UP MEANS FOR OVERRIDING DRIVES Frederick M. Littell and Simeon Budlong, Chicago, 111., assignors to F. J. Littell- Machine Company, Chicago, 11]., a corporation of Illinois Filed May 2, 1958, Ser. No. 732,624 3 Claims. c1. 2714.4

The invention relates to material feeding mechanism and has reference in particular to intermittent feeding mechanism employing a harmonic motion drive and to simple and efiicient lock-up means for the overrunning clutch of such a drive.

Metal working machines such as metal blanking and stamping machines and punch presses are operated in conjunction with mechanism whereby the metal strip material is conditioned and fed to the machine in measured lengths and at the highest possible speed for the required accuracy in order to obtain the maximum output for the machine. The several operating units which comprise the feeding mechanism are usually mounted in longitudinal alignment and the same are actuated from a main drive shaft through a ratchet or overrunning type of drive for positively bringing the feed rolls up to desired speed and which permits the rolls to overrun the drive under certain conditions. Ithas been necessary to apply friction braking pressures to such an overrunning type of drive so that the inertia of the rotating parts will not cause the feed rolls to override. If the feed rolls are permitted to override, the accuracy of the measured feed lengths is destroyed.

The continuously driven main operating shaft of the apparatus as illustrated is connected to the feed rolls by a reciprocating rack driving an overrunning clutch, the

rock having an operating stroke and a non-operating stroke for each revolution of the main shaft. Thus, the intermittent driving of the feed rolls results in the feeding of successive lengths of strip material. However, to ob tain perfect accuracy in the measured lengths of strip ma- 2,947,537 Patented Aug. 2, 1960 and which may be hydraulically applied before the end of the accelerating portion of the operating stroke and automatically released several degrees before the end of the decelerating portion of said stroke.

With these and various other objects in view, the inven tion may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings, which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts- Figure l is a side elevational view of a conditioning and feeding machine for strip material which embodies the improved lock-up means of the invention;

Figure 2 is a longitudinal sectional view taken approximately on line 2-2 of Figure 4; showing one of the operating shafts of the machine and illustrating the rack and pinion drive and the overrunning clutch with the lock-up means in associated relation therewith;

Figure 3 is a vertical sectional view of the rack and pinion drive taken approximately on line 3-3 of Figure 2;

Figure 4 is a sectional view of the clutch and lock-up means taken approximately on line 44 of Figure 2;

Figure 5 is a detail sectional view taken approximately on line 55 of Figure 4;

terial it is necessary to obtain similar accuracy in the rotation of the feed rolls. The feed rolls present a problem in control due to the necessary incorporation of an overrunning clutch in the drive.

An object of the invention is to provide lock-up means for overriding drives which will solve the control problem as regards the feed rolls in a highly efficient and satisfactory manner.

Another object of the invention resides in the provision of an overrunning clutch having combined therewith lockup means of the friction type.

A further object is to provide friction means which are uniquely combined with an overrunning clutch to form lock-up means for releasably locking the driving and driven members of the clutch and wherein the lock-up means may be applied and released hydraulically.

Another object is to provide lock-up means for the overrunning clutch as employed in rack and pinion drives with the result that control of the feed rolls is obtained for substantially the entire length of the operating stroke. The inertia of the rotating parts is thus prevented from causing over-feeding by the rolls so that the operating speed of the mechanism can be materially increased with greater accuracy in the measured lengths of strip material than has heretofore been possible.

Another object is to provide lock-up means of the friction type for overrunning drives .as herein described the invention is illustrated as applied to a straightening and feeding machine adapted to receive metal strip material, and after straightening and otherwise conditioning the strip material the same is fed by a pair of feed rolls to a punch press or similar machine for further processing of the material by means of pressing, punching, blanking or similar operations. The several parts going to make up the straightening and feeding machine 10 are supported or mounted by a housing structure such as indicated by numeral 11 and which includes a top wall 12, front and rear walls 13 and 14, and side walls 15. The maindriving shaft 16 is suitably journalled by the housing structure and said shaft has fixed thereto the worm gear 17 which has meshing relation with the driving pinion 18 for imparting rotation to said main operating shaft. The driving pinion 18 is connected by means, not shown,

. to a power source, such as an electric motor. The face plate 20 is suitably fixed to the main operating shaft 16 so as to rotate therewith and for the rack and pinion drive the said face plate is formed with a longitudinal groove 21 within which is mounted the threaded shaft 22. It will be seen from Figure 1 that the threaded shaft 22 is held to the face plate 20 by means of the washers 23 and which locate the threaded shaft within groove 21 in addition to mounting the same for rotation. The shaft may be rotated by applying a suitable tool to the squared end thereof and depending on the direction of rotation of the shaft, it will be understood that the stud shaft 24 can be adjusted along groove 21 either radially inward or radially outward. For this purpose the stud shaft 24 is made integral with or otherwise secured to a member in the form of a block, not shown, which rides within groove 21 and has threaded relation with the threaded shaft 22.

rotation of the main operating shaft 16, reciprocating movement is imparted to the rack. Since the stud shaft 24 may be adjusted longitudinally within groove 21 it is possible to vary the magnitude of the reciprocating strokes of rack 25. By rotating the threaded shaft 22 in a direction to locate the stud shaft .24 radially inward toward the main operating shaft the stroke of the rack is correspondingly reduced and when the threaded shaft .22 is rotated to move stud shaft 24 radially outward of the facing plate 20 the stroke of the rack is correspondingly increased.

The straightening and feeding unit consists of upper straightening rolls such as 28;and lower straightening rolls such as 30, the latter being geared to rotate in unison by the gear wheels 31 and the idler pinons 32. The upper rolls 28 of the straightening unit are each located centrally aboveapair of lower rolls and in order to accomplish a straightening function the upper rolls are adjustablymounted, being journalled by'the blocks 33 adapted to be moved vertically by means of the threaded studs 34. The metal strip material in passing through the straightening unit can be bent in a direction opposite to the curvature assumed by the metal strip when in coil form.

From the straightening unit the metal strip material passes through forward feeding rolls located at the forward end of the machine. The upper feeding roll 35 is suitably supported by the shaft 36 which is journalled for rotation in side frames provided by the machine. The lower feed roll 37 is similarly journalled by shaft 38 in side framesalso provided by the machine, such as frames 40 and-41, Figure 2. The end of shaft 38, as shown in Figure 2, is provided with ball-bearing races 42 for journalling the same in a substantially frictionless manner. It will be understood that shafts 36 and 38 are each provided with gear wheels (not shown) which have meshing relation with each other so that rotation of the lower feed roll shaft will effect rotation of the upper feed roll shaft. Thus the feed rolls will rotate in unison and to an equal extent for feeding successive lengths of strip material after the material has been properly conditioned. When it is desired to separate the upper feed roll 35 from its lower feed roll 37 the handle 43 is rotated in a clockwise direction and as long as the handle remains in a down position the rolls are held separated and which accordingly facilitates intial insertion of the strip material between the feed rolls. However, before starting operation of the machine the handle 43 is rotated in a clockwise direction to the position as shown in Figure 1, which position permits the feed rolls to close on the strip material located between the same. By means of the coil springs, such as 44, suflicient tension is maintained on the feeding rolls so that upon rotation thereof they will engage and grip the metal strip therebetween and feed the sameto the extent of their rotary movement.

The feed rolls of the straightening and feeding unit are rotated intermittently since intermittent rotation is imparted to the feed roll shaft 38 by the rack and pinion drive to be presently described and explained in detail. The extent of rotation of the feed rolls is adjustable in order that the lengths of the strip material fed by the machine may be varied, and in accordance with the inventionlock-up means are provided for the overrunning drive in order that control of the feed rolls can be maintained forsubstantially the entire length of the operating stroke with the result that the strip material can be fed to an accuracy of within one or two thousandths ofan inch and at a speed materially in excess of the feeding speeds heretofore employed.

The rack 25 has meshing relation with the pinion 46, both of said elements being housed Within'the rack and pinion housing 47 and which includes a cover plate 48 and a rear plate 50. The bodyportion of the rack and pinion housing issupported on trunnionsSl of the pinion 46 and, as shown in Figure 2, the pinion is journalled for free rotation on the left hand extending portion of shaft 38, there being interposed between the shaft and pinion suitable bearing sleeves such as 52. The trunnions 51 of the pinion 46 are integral therewith and said trunnions extend on respective sides of the pinion. The right hand trunnion is extended and has formed integral therewith the cylindrical casing '53 of the overrunning clutch indicated in its entirety by numeral 54. It will be understood therefore that the pinion 46 constitutes an integral unit with the cylindrical casing 53 of the overrunning clutch and which casing comprises the exterior driving member of said clutch. The interior or driven member of the overrunning clutch 54 is in the form of a hub 55 which is keyed as at 56 to the shaft 38 so that any rotation imparted to the hub member 55 will be transmitted to the feed roll drive shaft 38.

The hub member55 is provided with off-center gripping faces .57, as best shown in Figure 4, said faces being formed by the hardened .steel inserts 58 and which support and 1mount the grippingrrolls 60. The rollers are located between the gripping faces provided by the steel inserts 58 and the inside cylindrical gripping surfaces 61 of theannular casing 53. By means'of the pins 62, which are backed ,bythe coil springs 63, a one-way clutch is provided whereby only one reciprocating stroke of the rack will be transmitted to shaft 38. The position of rack 25 on the right hand side of pinion 46, Figure 3, and the particular orientation of clutch hub 57 is such that movement of the rack 25 in a downward direction constitutes an operating stroke of the rack, producing rotation of shaft 38 and rotation of the feeding and straightening rolls for a feeding operation. Conversely, reciprocating movement of rack 25 in an upward direction constitutes a non-operative stroke, with the result that no rotation is imparted through the one-way clutch to shaft 38. Side plates such as 64 complete the hub structure and it will be observed that said side plates, which are securedto hub 55 by screws 65, serve to retain the rollers 60, pin 62, and spring 63 in operative relation with each other withinopenings provided therefor by the hub.

As best shown in Figure 4, it will be observed that the hub 55 is provided with six gripping rolls, the same being located around the periphery'of the hub and being spaced approximately sixty degrees from each other. The lockup means of the invention are located between the gripping rolls, being also mounted by hub 55 and located at sixty degree intervals around the periphery of the hub. Each lock-up .means essentially comprises a piston 67 having location within acylindrical recess 68 formed in the hub 55 and being adapted to reciprocate within the recess although to a slight extent only. For sealing purposes each piston may be equipped with packing piston rings, or the like, such as 70, since a liquid Within the recesses is compressed in order to force the pistons in a radial outward direction into frictional contact with the inside surface 61 of the annular casing '53. Thishydraulic actuation of pistons 67 will lock the hub 55 to the annular casing 53 and thus in this manner the inertia of the rotatingparts during the decelerating portion of the operative stroke of the rack is prevented from causing overfeeding by the rolls and as a result extremely accurate lengths are obtained. For hydraulically applying and releasing the pistons 67 the cylindrical recess for each piston. is connected by passages 71 and 72 to the longitudinal bore 7=3formed in the left hand end of the feed roll shaft 38. The connection 74 at this end of the shaft includes a rotary seal '75 which in turn connects with conduit 76 which conducts liquidto the bore 73 and to the passages leading to the piston recesses. It is neces-v sary. to apply a pressure to the liquid to hydraulically actuate the pistons, causing movement thereof in a radially outward direction into. lock-up engagement with casing 53. I However, it is. possible to instantly release the pistons merely by releasing the hydraulic pressure on the liquid within the passages and bore.

The numeral 77 indicates friction braking means such as may be applied to shaft 38 for eliminating backlash in the gearing. The housing 78 of the friction brake is held stationary by suitable means, whereas a plurality of friction discs 79 are keyed at 80 to shaft 38 so as to rotate with the shaft. The action of the rotating friction discs with respect to the stationary housing provides a low inertia, fixed type of disc brake such as will apply a constant drag to the roll feed shaft 38. Accordingly, at the end of the operative stroke of the rack, with the lockup means released and upon reversing movement of the rack, if it were not for the friction brake 77 there would be a tendency for the feed rolls to reverse at least to an extent as permitted by the backlash in the gearing. However, the constant drag provided by friction bnake 77 prevents any such reverse movement of the feed rolls and thus greater accuracy in feeding of the measured lengths is obtained.

In the modification of Figure 6, a plurality of friction discs are provided for the lock-up means and wherein their coaction is controlled by a plurality of pistons hydraulically actuated in a manner similar to that described with respect to Figures 1 to 5 inclusive. The rack 125 has meshing relation with the pinion 146 journalled for free rotation on the feed roll shaft 38. The pinion and rack are located within the housing 147 and the trunnion 151 on the right hand side of the pinion is extended so as to have formed integrally therewith the cylindrical casing 153. The hub 155 is keyed to shaft 38 as at 156 and said hub carries a plurality of gripping rolls 160 which are backed by spring-pressed pins 162, all in a manner as fully described and as disclosed in Figures 2 and 4. The pistons 167 are located in recesses 168 formed in the hub, the said recesses each being closed at one end by the threaded plugs 169. At the opposite end each piston has contact with a pressure plate 170 which is held to the hub 155 so as to rotate therewith but which may have movement axially of the hub.

A similar pressure plate 171 is fixed to the cover 172 which is part of the cylindrical casing 153, being releasably secured thereto by the bolts 173. Between pressure plates 170 and 172 there is located a number of friction discs 174 and 175. The friction discs 174 are held to the hub in a manner similar to pressure plate 170, whereas friction discs 175 are held to the cover and in a manner similar to pressure plate 171. The pistons 167 are therefore operative to apply axial pressure to the friction discs to cause such contact of one disc with an adjacent disc as to lock the hub 155 to the casing 153. The friction discs are accordingly a form of lock-up means for the overrunning clutch 154 and for hydraulically actuating the pistons 167 passageways 176 and 177 are provided and which communicate with the bore 178 extending longitudinally of shaft 38. A pressure can be applied to the liquid within the bore and passageways to cause movement of the pistons for locking up the overrunning clutch. Upon release of this pressure the pistons automatically release their action with respect to the friction discs and thus the lock-up means are released.

In the modification of Figure 7 the lock-up means takes the form of a pair of friction side plates provided with diagonal friction-engaging surfaces. The cylindrical casing 253 is provided with a cover plate 280 having the inwardly directed diagonal surface 281, and wherein the cover plate is secured to the casing by the bolts 282. The hub 255 of the overrunning clutch of Figure 7 is keyed to shaft 38 by key 256 and said hub carries the gripping rolls 260 which are backed by spring-pressed pins 261. The action of the gripping rolls 260 is the same as previously described although in this modified form of clutch a pair of pistons 283 and 284 are employed as a substitute for each piston 67 and 167 as employed in the structure shown in Figures 2 and 6, respectively. Piston 283 has a reduced end 285 which fits within an opening formed in the friction side plate 286, said plate having its diagonal friction surface 287 in contact with surface 281. In a similar manner piston 284 has a reduced end portion 288 located within an opening in the friction side plate 290. The diagonal surface 291 of this side plate 290 has contact with surface 292 formed interiorly of casing 253. When the pistons 283 and 284 are forced apart their action is to increase the frictional contact of the side plates with the casing and said friction contact can be made sufficiently great to lock the hub 255 to casing 253. Accordingly, said friction side plates 286 and 290 comprise the lock-up means for the overrunning clutch 254 of this modification. The liquid for actuating the pistons 283 and 284 is conducted by the longitudinal bore 278 and by the passageways 276 and 277. When said liquid is placed under pressure, piston 283 is forced in a direction toward the right, whereas piston 284 is forced in a direction toward the left, and this separation of the pistons will render the lock-up means operative. When the pressure is released said lock-up means is likewise released.

The lock-up means of the invention has eliminated the friction braking formerly employed as disclosed for example in the Littell and Wiig Patent No. 2,758,837 granted August 14, 1956. In actual operation the lockup means may be applied during the accelerating portion of the operative stroke so that the driving and driven members of the overrunning clutch are locked together at the beginning of the decelerating portion of the operative stroke. The members remain locked upalmost to the end of the operative stroke although the actual point of release is not critical and will depend on the inertia of the rotating parts. The greater the inertia the longer the members of the clutch will remain locked or, in other words, the release of the lock-up means may be delayed until a few degrees before the end of the operative stroke in, those operations where the inertia is excessive due to mass of the rotating parts or due to high speeds or both.

Also the pistons of the lock-up means can be actuated pneumatically, mechanically or electrically as well as hydraulically as described. It is of course necessary to time the piston actuations with the operative strokes of the clutch and this can be accomplished by any conventional means adapted to the transmission medium such as may be employed.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In a machine of the class described, the combination with feeding rolls for feeding strip material, of a feed roll drive shaft, intermittently operating driving means for rotating the feed roll drive shaft to cause feeding of measured lengths of said strip material, s-aid driving means means including an overrunning clutch having an annular outer casing comprising the driving member and an interior clutch member fixed to the feed roll drive shaft and comprising the driven member of the clutch, lock-up means for frictionally and releasably locking the clutch member to the casing, said lock-up means comprising a plurality of pistons mounted by the clutch member for reciprocation and friction elements provided and carried by the clutch member and easing respectively, and means for hydraulically actuating the pistons to cause the friction elements to engage whereby to render the lock-up means operative.

2. In a machine of the class described, the combination with feeding rolls for feeding strip material, of a feed roll drive shaft, intermittently operating driving means for rotating the feed roll drive shaft to cause feeding of measured lengths of said strip material, said driving 'meaiis'in'cluding' an over-running clutch having an anfi'ular outer casing comprising the driving member and an interior hub keyed to the feed roll drive shaft and comprising the driven member of the clutch, lock-up means for frictionally and releasably locking the casing to the interior hub, said lock-up means comprising a plurality of 'pistons mounted by the hub for reciprocation and friction elements carried by the casing and hub respectively, and means for actuating the pistons to cause the friction elements to engage whereby to render the lock-up means operative.

3. In a machine of the class described, in combination with feeding rolls for feeding strip material, a feed r'oll drive shaft, a one-Way clutch on the feed roll drive shaft including a driven hub fixed to the shaft and a driving casing journalled for free rotation on the shaft, a recipr'oeat'in'g member for rotating the feed roll drive shaft through the said one-way clutch, whereby the member has an operative stroke and a return inoperative stroke to intermittently rotate the feed roll drive shaft for feeding measured lengths of strip material, and whereby each operative stroke includes an initial accelerating portion 8 during which the torque is a maximum for rotating the feed rolls and for accelerating the'rri, and also includes a't'errninating decelerating portion'o'f lovv'torque since the feed'r'o'lls have a tendency to overrun due to the one- References Cited in the file of this patent UNITED STATES PATENTS 1,846,745 Merritt -3 Feb. 23, 1932 2,301,930 Oattaneo Nov. 17, 1942 2,333,682 Schneider mu Nov. 9, 1943 2,408,506 Bi'iskin et al. Oct; 1, 1946 2,449,588 Kegresse Apr. 27, 1948 2,648,416 Krueger -2 Aug. 11, 1953 2,758,837 Littell et "a1. Aug. 14, 1956 

